A cleansing agent is required to have a variety of functions such as emulsifying or cleaning the components of dirt and stains such as oil. Especially, unlike an industrial cleaner, a laundry cleaner, and a house cleaner, it is considered important that a cleansing agent used for skin or hair has not only detergency and excellent foaming performance, but also a favorable durability of foam, rinse feel and a good feel after rinsing and drying. Particularly in the case of hair, good finger combability and softness of the hair during rinsing and after drying are desired, and in the case of skin, such an impression is desired that a refreshing feeling is imparted to the skin after washing with a cleansing agent.
Under the foregoing circumstances, olefin sulfonate, which is one of the anionic surfactants, is generally obtained by sulfonating olefin through reactions with a gaseous sulfur trioxide-containing gas, followed by neutralization and then hydrolysis of the resulting sulfonic acid. Olefin sulfonate is used in various cleansing agents.
For example, Patent Document 1 discloses a cleansing composition containing a specific internal olefin sulfonate for the purposes of increasing the solubilizing ability, penetrating ability, and interfacial tension reducing ability, and describes that when the above cleansing composition is used as a shampoo, it lathers well without friction, and achieves an improved feel. Also, Patent Document 2 discloses a cleansing composition containing a specific internal olefin sulfonate for the purposes of improving detergency, and describes examples of application to shampoos and the like, and Patent Document 3 also describes an aqueous liquid cleansing agent containing a specific internal olefin sulfonate and having a low cloud point.
On the other hand, Patent Document 4 discloses a cleansing composition containing an olefin sulfonate and a low-viscosity hydrophobic silicone oil such as octamethyltetrasiloxane or decamethylpentasiloxane to improve smoothness and dry touch of hair after drying. Patent Document 5 discloses a shampoo composition containing higher secondary alcohol alkoxylate sulfate having a specific structure as the composition which is low-irritant to skin or the like and can enhance detergency.